EditorWindow: Toolbar - Button cross position

Hello,

I'm actually trying to make an editor tool bar for my project. This one will help me to make levels.

I have some difficulties to implement my buttons. I read a lot about GUILayout.BeginArea and GUILayout.BeginHorizontal and I found it a little bit complicated.

I would like to position my button like a cross. It's probably a question of logic between BeginArea, BeginHorizontal and BeginVertical, but I just need help for it. I attach my code and a picture to explain better my problem.

Thanks

 GUILayout.BeginArea(new Rect(0, 5, 150, 70));
         GUILayout.BeginHorizontal();
         if (GUILayout.Button(ArrowLeftPic,  GUILayout.Width(30), GUILayout.Height(30)))
         {
             MessageTypeConsole = MessageType.Info;
             ConsoleText = "Room Block correctly Added!";
             //EditorWindow.GetWindow<KnightMenu>(false, "trucMachin");
         }
         GUILayout.BeginVertical();
         if (GUILayout.Button(ArrowUpPic,  GUILayout.Width(30), GUILayout.Height(30)))
         {
             MessageTypeConsole = MessageType.Info;
             ConsoleText = "Room Block correctly Added!";
             //EditorWindow.GetWindow<KnightMenu>(false, "trucMachin");
         }
         if (GUILayout.Button(ArrowDownPic,  GUILayout.Width(30), GUILayout.Height(30)))
         {
             MessageTypeConsole = MessageType.Info;
             ConsoleText = "Room Block correctly Added!";
             //EditorWindow.GetWindow<KnightMenu>(false, "trucMachin");
         }
         GUILayout.EndVertical();
         if (GUILayout.Button(ArrowRightPic,  GUILayout.Width(30), GUILayout.Height(30)))
         {
             MessageTypeConsole = MessageType.Info;
             ConsoleText = "Room Block correctly Added!";
             //EditorWindow.GetWindow<KnightMenu>(false, "trucMachin");
         }
         if (GUILayout.Button("Corridor Properties",  GUILayout.Width(ButtonPropertiesSizeWidth), GUILayout.Height(ButtonPropertiesSizeHeight)))
         {
             MessageTypeConsole = MessageType.Info;
             ConsoleText = "Openning Corridor Properties Sub Menu..";
         }
         GUILayout.EndHorizontal();
         GUILayout.EndArea();